Conservative columnist George Will created a bit of a stir by suggesting that neither Mitt Romney nor Rick Santorum “seems likely to be elected,” and that at some point it may be in the best interest of Republicans to focus their attention on “retaining control of the House and winning control of the Senate.”

Will is right to stress the importance of Congress. The president is the head of the government, and receives the lion’s share of the media attention, but without the support of Congress it’s pretty near impossible for him do much in the way of sweeping reform. All three of the Republican candidates have mentioned how radical Obama could be in his second term without having to worry about re-election. But, what all three are well aware of, but conveniently forget to mention, is that Obama will not have the advantage of large Democratic majorities in the House and Senate. As Ezra Klein notes, “the single most important accomplishment of [Obama’s] second term would be protecting the gains of his first term.” If you need any evidence of Congress’s power to restrain the president, take a look at Obama’s meagre political agenda for the year.

However, there’s an important point that Will’s column overlooks; you cannot quarantine the presidential election off from the other House and Senate races. If voters are excited about the Republican candidate, they’ll be more likely to show up at the polls, and in many cases vote Republican all the way down the ticket. This is the presidential coattails effect, and it’s been well established by academic research.

Republicans should certainly focus much attention on picking up Senate seats, but they need to be strategic about how they go about it. If the message is, hey the guy at the top of the ticket is pretty boring but you should still vote for me, it’s going to turn off voters. For better or for worse, the fate of Republican candidates in the upcoming election is in large part tied to their eventual nominee.